The present invention relates to a hand-held scroll saw having a sawing blade which is moved upwardly and downwardly by a motor to cut a workpiece along a desired curve.
Since the compressive strength of the sawing blade of a scroll saw is very low, a first end of the blade is coupled to the lower end of a piston, which is moved upwardly and downwardly by a motor. The blade is supported at a second end thereof by a U-shaped arm, provided so as not to interfere with a workpiece, and the blade is pulled downwardly at the second end. Thus, the blade is reciprocated by upward and downward movement of the piston while always keeping the blade taut.
Conventional scroll saws have been provided previously which are of the heavy, fixed-installation type, as disclosed in Japanese Patent Examined Publication Nos. 3158/77 and 20720/78. A workpiece is cut along a desired curve by the conventional scroll saw, while the workpiece, positioned on a table, is turned relative to a sawing blade.
In a hand-held scroll saw, no table is provided, and a workpiece is not turned relative to a sawing blade. Instead, the workpiece is fixed in position. Hence, the hand-held scroll saw requires not only a U-shaped arm thereof to be compact, but also a blade support device for reciprocating the blade while keeping the blade taut. In the hand-held scroll saw, construction of the blade support device is paramount over making the U-shaped arm compact. Thus, the blade support device of the hand-held scroll saw cannot be constituted similarly to the scroll saws of the heavy, fixed-installation type, nor manufactured by making the blade support device, with components equivalent to the scroll saws of the heavy, fixed-installation type, compact. Additionally, since the range of the workpiece cut off by the hand-held scroll saw would be made narrow if the U-shaped arm thereof is made compact, the range must be prevented from being made narrow by making the U-shaped arm large and cumbersome. Thus, in conventional hand-held saws, a compact hand-held scroll saw with a suitable range cannot be achieved. This presents a problem.